From 95d92ffb28c8c9607188903351f6c916fbdf292a Mon Sep 17 00:00:00 2001
From: Rohit Bindal <rohitkumarbindal@iipe.ac.in>
Date: Fri, 22 Oct 2021 18:44:14 +0530
Subject: [PATCH] Create Bipartite_checker.cpp

---
 .../Algorithms/Graphs/Bipartite_checker.cpp   | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 dsa-roadmaps/Beginners/Algorithms/Graphs/Bipartite_checker.cpp

diff --git a/dsa-roadmaps/Beginners/Algorithms/Graphs/Bipartite_checker.cpp b/dsa-roadmaps/Beginners/Algorithms/Graphs/Bipartite_checker.cpp
new file mode 100644
index 0000000..3dcfb6b
--- /dev/null
+++ b/dsa-roadmaps/Beginners/Algorithms/Graphs/Bipartite_checker.cpp
@@ -0,0 +1,87 @@
+#include <bits/stdc++.h>
+using namespace std;
+ 
+#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+#define endl "\n"
+#define int long long
+#define pb push_back
+
+//Bipartite Graph Checker
+
+class Graph
+{
+    map<int, list<int>> l;
+
+    public:
+    void addEdge(int x, int y)
+    {
+        l[x].pb(y);
+        l[y].pb(x);
+    }
+   
+
+  bool dfs_helper(int src, map<int,int> &visited, int parent, int col)
+   {
+       visited[src] = col;
+      
+       for(auto nbrs: l[src])
+       {
+           if(visited[nbrs]==0)
+           {
+            bool mila =  dfs_helper(nbrs, visited, src, 3-col);
+            if(mila==true)
+            {
+                return true;
+            }
+           }
+           else if(nbrs!=parent && visited[nbrs]!=col)
+           { 
+             return true;
+           }
+       }
+       return false;
+   }
+
+    void dfs(int src)
+    {
+        //if value of visited[node]=0 means that the node is not visited yet
+        //if value of visited[node]=1 means that the node is already visited and the node is colored as 1
+        //if value of visited[node]=2 means that the node is already visited and the node is colored as 2
+        map<int,int> visited;
+
+        for(auto pair:l)
+        {
+            auto node = pair.first;
+            visited[node]=0;
+        }
+
+        bool check = dfs_helper(src, visited, -1, 1);
+        if(check)
+        {
+            cout<<"Bipartite";
+        }
+        else
+        {
+            cout<<"Not Bipartite";
+        }
+        
+
+    }  
+
+};
+
+int32_t main()
+{
+  IOS;
+  Graph g;
+  //if graph have a odd cycle then the graph will not be a bipartite
+  g.addEdge(1,2);
+  g.addEdge(4,5);
+  g.addEdge(5,1);
+  g.addEdge(3,4);
+  g.addEdge(3,2);
+  g.dfs(1);
+
+  return 0;
+}
+